I am trying to figure out what the correlation is between the Throttle, Injection Pump, and PMD (Pump Mounted Driver) in the 6.5 diesel. The intermittent throttle problem is getting annoying, the other day it did it bad enough I had to turn the truck off, then when it started, the transmission did not shift correctly for a few miles. The one thing all of these things have in common is the previous owner, at this point I am not sure I trust anything he did and unfortunately he swapped the engine. I am going to review all the grounds and see if there is an issue there, then I am going to swap the PMD for a new one, change the fuel filter for good measure and try it out again. The throttle is still dropping out and now I get occasional surging that I never had before. Everything that I have read makes me think that it is either the wiring harness or the actual PCM (Powertrain Control Module). The throttle pedal has three separate sensors in there and it should function normal with one bad one, then function with a warning lamp with two bad ones, then go into idle only mode if all three are bad. The PCM sends signals to the PMD and Injection Pump based on inputs from the pedal. I have changed the pedal three times, once with a NOS one, and twice with known good ones from other trucks. I am sure there are other things involved, but I haven't figured it out yet, most of the time I never get any codes other than a Service Throttle Soon light. The funny thing is it has not been as bad this year as it was last year, but I haven't done anything that would have effected it. I hate intermittent problems, if it would just stop working completely, then at least you would have something to lean towards.